Telephone signal apparatus.



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APPLIGATION FILED JUNE 13.1905- 2 SHEETS-SHEET 2.

Witnesses' Inventor,

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`\ Attorneys UNITED sTATEs 'PATENT oEEIoE.

DAVID FRAME LAUGHLIN, OF CLLYDE, KANSAS, ASSIGNOR F .ONE-HALF T()FRANKLIN H. BUTLER, OF CLYDE, KANSAS.

TELEPHONE SIGNAL APPARATUS.

Specification of Letters Patent.

Patented Sept. 19, 1905.

Application iiled .Tune 13, 1905. Serial No. 265,062.

To @ZZ whom, it may concern:

Be it known that I, DAVID FRAME LAUGH- LIN, a citizen of the UnitedvStates, residing at Clyde, in the county of Cloud and State of Kansas,have invented a new and useful Telephone Signal Apparatus, of which thefollowing is a specification.

This invention relates to selective signaling systems, and has for itsprincipal object to provide what may be termed a sympathetic system,wherein the vibrations of duplicate pendulums subject to the sameinfluence are employed for the purpose'ot` closing electrical circuits.

It is well known that simple pendulums of precisely the sameconstruction and subjected to the same iniiuences will have the sameam-y plitude of vibration and will move through equal arcs in the sametime. This fact is taken advantage of in the present instance byemploying at a number oiI stations pendulums oi' diiferentcharacter-that is to say, the responsive pendulum at each stationdiifers either in length, weight, or size from all of the otherpendulums in the remaining stations, and at a central station arearranged a number oi' calling-pendulums that are duplicates oi' those inthe remaining stations. The term calling-pendulum is employed throughoutthe specification and claims tov designate a pendulum which is set inmotion at the central station for the purpose of calling anotherstation, and the term responsive 'pendulum is employed to designate apendulum which vibrates sympathetically with the calling-pendulum, andis moved at a distant station to control the circuit at that station.

The principal object of the invention, there-l fore, is to provide asimple form oi' selective signaling system, whereby any selected Stationmay be placed in communication with another without the knowledge of anyof the intervening stations, this being of especial value on party-lineswhere in ordinary systems a call made by one subscriber is sounded atall of the other stations along the line.

With these and other objects in View, as.

will more fully hereinafter appear, the invention consists in certainnovel features of con- 5o after fully described, illustrated in theaccompanying drawings, and particularly pointed out in the appendedclaims, it being undery through said electromagnet.

struction and arrangement of parts hereinstood that various changes inthe form, proportions, size, and minor details of the structure may bemade without departing from the spirit or sacrilcing any of theadvantages of the invention.

In the accompanying drawings, Figure l is a diagram of a selectivesignaling system larranged in accordance with the invention. Fig. 2 is adetail perspective view of the selecting devices employed at eachsubstation. Fig. 3 is a'sectional elevation of the same. Fig. 4 is adetail view of a calling mechanism employed at a central station.

Similar characters of reference are employed to indicate correspondingparts throughout the several gures of the drawings.

All of the local stations are shown as bridged between two main wires 1and 2, and at station A in Fig. 1 the `parts are in the normal positionwith the receiver-hook down and the talking-circuit disconnected. `Atstation B the selective circuit is shown as connected andthetalking-circuit bridged between the main-line wires. i

The receiver-hook 3 is pivoted at 4, and it carries at a pointintermediate of its length a contact-plate 5, that is insulated from theremaining portion of the hook. Bearing against this contact-plate aretwo contacts 6 and 7, the contact 6 being connected by a local wire 8 tothe main-line wire 2 and the contact 7 being connected by a local wire 9to the main line 1, and in said local line 9 is connected anelectromagnet 10, there being one of such magnets at each of thestations, and the circuit, as indicated at 1, being normally closedWithin the field of force of the electromagnet 10 is a pendulum 11,which mayr carry an armature 12. The construction of this portion of themechanism will be more fully described hereinafter.

The rear end of the receiver-hook is bent downward, forming an arm 13,that is pro vided with a shoulder 14, having a small block of insulatingmaterial vin its upper face, and this block is arranged rto receive thefront end of a circuit-closing arm 15. The arm 15 is pivoted forswinging movement in a vertical plane and always tends to reassume thesame plane, so that when moved outward from the shoulder during aselecting operation it will move inward in order to be in position to beIOO rengaged by said shoulder, as more fully described hereinafter. Thisarm when released from the influence of the receiver-hook or whenallowed to move downward with the receiver-hook when the receiver isremoved will engage a contact-arm 16, andthis will lose the calling andtalking circuits of the At a convenient point in the local station isarranged a call-bell 17, one binding-post ot' Which is connected by aWire 18 to the mainline Wire 1. From the other binding-post extends aWire 19 to a contact 20, that is engaged by the receiver-hook when theouter end of the latter is depressed. The circuit is continued when thereceiver is on the hook through thehook and through a contact 21 andWire 22 to the circuit-closing arm 15, and if the latter is inengagement With the contact-arm 16 the circuit Will be completed throughthe latter and through Wire 23 to the main-line wire 2, so that it' thearms 15 and 16 be engaged While the receiver is still on the hook thecalling-circuit Will be established.

One binding-post of the receiver R is connected by a Wire 24 to thecontact-arm 15 and `the opposite binding-post is connected by a wire 25to the secondary of the inductorium I and thence to the main-lineWire 1. If the contact-arm 15 is down in engagement with thecontact-arm16, the receiver-circuit Will be established from main-line Wire 1, Wire25, the secondary, the receiver, Wire 24, contact-arms 15 and 16, Wire23 to main-line Wire 2.

The primary circuit includes a transmitter T, a Wire 26, battery B, andcontacts 27, that are normally disengagedfrom the receiverotherresponsive pendulums at all of the other.

stations in the line. It may be longer or shorter or it may havea'different period or amplitude of vibration or it may be of differentwidth, and thus be more or less retarded by the air.

Each of the pendulums may be formed of soft iron or may carry asoft-iron armature arranged Within the field of force of theelectromagnet- 10, and when the latter is energized the pendulum Will beattracted and when denergized the pendulum will start its movementtoward the position of equilibrium and pass beyond the same by virtue ofits acquired velocity. When the lirst half of a complete period has beenreached, the electromagnet is again energized and the pendulum 1s oncemore attracted, the magnet belng kept energized during the Whole of thesecond haltI period of movement and then denergized exactly at thecompletion of such half period. It may require two or three 'or evenmore movements to effect the desired amplitude of vibration of thependulum; but in each case the energizing and denergizing of theelectromagnet must occur exactly at the comple-v tion of half periods ofmovement of said pendulum. When the pendulum has finally acquired itspredetermined amplitude ot' vibration, it Will strike against thecontact-arm 15 and move the same from the shoulder 14 of thereceiver-hook, the contact-arm moving by gravity into engagement withthe contact-arm 16, and thus, as before described, completing thecalling-circuit, so that a current sent along' the line Will cause thesounding of the bell 17.

To effect movement of the pendulum, the

central station is provided with a set of calling-pendulums 11', therebeing a calling-pendulum the eXact duplicate of each responsivependulum. These calling-pendulums may be arranged in Aany suitablemanner, and when any particular substation is to be called its duplicatecalling-pendulum at central is arranged Within the field of force of anelectromagnet 30. This electromagnet 30 is a du plicate of all of theother electromagnets 1() in the line, and all of said magnets areconnected in the same circuit and all subjected to precisely the sameinfluences. The electromagnet 30 is placed opposite the desiredcallingpendulum and a circuit is then closed through a source ofelectrical energy 31 by a suitable key or switch 32. As a result everyelectromagnet along the line is energized, including the electromagnet30, and the single'callingpendulum and every one of the responsive Ypendulums will be attracted.

When the callingpendulum has reached the limit of its movement in thedirection of the magnet, the circuit is immediately opened. It has beenstated that all of the responsive pendulums are attracted; but in nocase,with the exception of the responsive pendulum corresponding to thecalling-pendulum, has any pendulum arrived at its exact period when thecurrent is cut off. The calling-pendulum and the duplicate responsivependulum then start at precisely the same time on the second half periodof movement and move in unison until the second halt' period has beenaccomplished, While the operator watching the calling-pendulum may closethe circuit and again energize all of the electromagnets.

While all of the responsive pendulums have started on their second halfperiod during the movement of the selected responsive pendulum, themovement is irregular and occurs either before or after the correcttime, and this is accentuated when said pendulums arrive at the end oftheir rst halt' periods, the second closing of the electromagnetoccurring at the proper time for the selected responsive.

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pendulum, but not at a time which will permit proper action of thenon-selected responsive pendulums.

-In operation any substation will call central by short-circuiting theline 18 19 through a battery 34 by aswiteh 35. He then removes hisreceivel` from the hook, and thus allows the contact-arm 15 to descendinto engagement with the contact-arm 16 and 'completes thetalking-circuit. The subscriber then asks for the required number andthe central-station operator moves the electromagnet 30 in front of thedesired calling-pendulum and starts the movement, as beforedescribed,until the responsive pendulum at the selected station strikesthe arm 15 and causes it to fall into engagement with the arm 16, thusestablishing a calling-circuit at the selected station, and a currentthen sent along the line will energize the calling-bell ofthe selectedstation. The subscriber at the called station then removes his receiverfrom the hook and by closing the primary circuit is enabled to conversewith the calling subscriber.

It will be observed that with an apparatus of this character all of thetelephone instruments in the line are disconnected and will not beinjured during an electrical storm, and, further, that any substationmay be called up without the knowledge of any of the other stations.

Having thus described the invention, what is claimed is-r 1. Insignaling apparatus, a pair of superposed contact members, areceiver-hook having its inner end arranged to form a support for theupper member, the removal of the receiver from the hook permitting suchupper member to descend into engagement with the lower member, and thereplacing of the receiver serving to separate said members, and

posed contact members, a receiver-hook having at its inner end aninsulated support for the upper member, and provided with apendent armarranged in a plane oblique to the vertical plane of said upper member,and an electromagnetically-controlled pendulum for moving said uppermember from its support.

4. In signaling apparatus, a lower contact member in the form of a barhaving an inturned arm at one end, a second contact member arrangedabove the iirst and adapted to engage said arm to close a circuit, apivotallymounted receiver-hook having at its inner end a support forsaid upper member, and provided with a pendent inclined arm to permitrengagement with said upper member after a circuit-closing operation,and an electromagnetically controlled pendulum for moving said uppermember from its support.

In testimony that I claim the foregoing as my own I have hereto axed mysignature in the presence of two witnesses.

DAVID FRAME LAUGHLIN.

Witnesses:

W. D. GROFF, JOHN G. NICHOLAS.

